'Ali ibn Abi Talib is unparalleled in Islam. He was the Prophet Muhammad's cousin and son-in-law, the first Shi'i Imam and the fourth of the Rashidun Caliphs. Sunni and Shi'i Muslims alike hold 'Ali in the highest regard owing to his status as a spiritual teacher and his strength as a warrior. According to the mystical tradition of Islam, 'Ali is the embodiment of 'the perfect human being' (al-insan al-kamil). Reza Shah-Kazemi here draws on the insights of the Sufi masters Ibn 'Arabi and Rumi to look beyond the biographical details of 'Ali's life to reflect on the spiritual significance of his actions and teachings. In the spirit of ta'wil or esoteric interpretation, the author identifies how 'Ali's inner spiritual principles can be regarded as transcending the boundaries of time, space, religion and culture. For Shah-Kazemi, it is this mystical interpretation of 'Ali that invites a new, much deeper understanding of his personality and contemporary relevance, outside the confines of history. The book offers vivid examples of 'Ali's conduct and persona--on the battlefield, from the pulpit of the mosque, and in his private teachings to the mystics--exploring the ways in which his actions embodied his principles. An accessible and concise guide, this book is relevant to all those with an interest in the life of 'Ali, Islamic spirituality, religious practice, and the philosophy of religion.